Twitter Bootstrap 3 RC 1: most important changes

Twitter Bootstrap, the most popular CSS framework is heading towards version 3 and here are the most important changes. I almost jumped when I saw the bootstrap blog entry in my RSS reader this morning!

Grid System classes now ‘.col-‘

The grid system classes have been changed, I assume to avoid confusion and to prevent people not rewriting their markup, since the way grids work have been alterted a lot. Also it is responsive by default and there’s no need to either decide or include bootstrap-responsive.less.

You now can choose between classes like .col-sm for small grid, .col-lg for large grid or go tiny with .col. This means that you can more specifically target how your site works on smartphones and tablets in contrast to desktop screens. Read more about how grid systems have changed in the official documentation.

Through lines like

div.sidebar {
make-column(3);
}

You can now make elements behave as columns, even though they don’t have the markup on the element itself.

Bootstrap Flat Design

Flat is the new gradient in Twitter Bootstrap 3. They have not given up on the round corners completely, but it’s definitely become very plain

Complete Changelog

The complete changelog is available here and if you’re interested in how one of the biggest CSS frameworks in the world is built, it’s a good read. Also it’s great if you want to use Twitter Bootstrap 3 and don’t want to run into everything that has changed by yourself.

You can also see which points are still to go (the unchecked ones).

Ready for use?

Bugs will occur and they will be fixed. I’ll start playing around with it, but since it’s been in development quite some time, I expect that the most vital things like the grid and form elements are working properly. I would not fear to put it into production, even though it’s a release candidate. Twitter Bootstrap 3 looks great and is a meaningful iteration! If you have things running on Bootstrap 2.3 or are developing themes for it, now seems the time to upgrade!

Thank you for reading! If you have any comments, additions or questions, please leave them in the form below! You can also tweet them at me